Roller bit



I Sept. 4, 193 G. G. HARRINGTON ROLLER BIT I Filed March 7, 1932 2Sheets-Sheet l wk Qvmm a I rill I ("eorqe G Harrington INVENTOR Y flmmhaATTORNEY p 4, 1934- G. G. IHARRINGTCI N 1,972,298

' ROLLER BIT Filed March 7, 1932 2 Sheets-sheaf; 2

' Geqrye GHarr-ingion INVENTOR ATTORNEY the other of said pins;substantially cylindrical cutters on said two pins projecting outwardlyprojections having a downwardly opening slot and a bolt openingextending upwardly from said slot; a cutter support having a post insaid post opening, and three cutter pins projecting upwardly andoutwardly into said slots; bolts connected to the ends of said pins andextending upwardly into said bolt openings; roller cutters on said pins;said support, cutters and bolts being slidable into said head as a unit;and means to hold said post and bolts in said openings.

6. A drill bit having a central post opening and three depending bearingprojections at substantially equal distances apart, each of saidprojections having a downwardly opening slot; a cutter support having apost in said post opening, and three cutter pins projecting upwardly andoutwardly into said slots; roller cutters on said pins; said support andcutters being slidable into said head as a unit; and means to hold' saidpost in said opening.

7. A drill bit head having three depending bearing projections atsubstantially equal distances apart, each of said projections having adownwardly opening slot; a cutter support having three cutter pinsprojecting upwardly and outwardly into said slots; roller cutters onsaid pins; said support and cutters being slidable into said head as aunit; and means to hold said support in said head.

